Seat covers made from a film of plastic are put on the vehicle seat to protect the seat from dirtying by workers or other people. Such seat covers are known in garages if a repair or an inspection of the vehicle has to be performed. Even during the first mounting of a vehicle in an automobile factory there is the danger of dirtying the seats. This danger of dirtying even begins at the manufacturer of the vehicle seat and during transport to the automobile factory. This danger lasts when putting the seats to conveyor equipment leading to the assembly line. In addition, the vehicle seats have to be placed into the chassis. During this mounting operation a large number of workers one after the other have contact with the seats. Finally, the assembled vehicle has to be driven away from the assembly line onto trucks or railway waggons for transport and the vehicle has to be moved several times at the dealers place prior to sale and delivery to the individual buyer. For the weight of the vehicle seat is increasing especially due to the mounting of adjusting motors and other elements, it becomes more and more arduous to mount the vehicle seats manually by the worker into the chassis. Mounting by robots is preferred on the assembly line. A robot used for this purposes comprises a mounting plate which is pressed into the gap between the seat cushion and the backrest of the seat, the seat being in normal position. Often the robot is designed to convey and mount the seats in pairs into the interior of the chassis. After mounting the mounting plate is retracted from the gap between the backrest and the seat cushion. Using known seat covers the mounting plate would penetrate the front layer of the seat cover so that the protecting effect of the seat cover is substantially decreased. Experiments have been made by loosening the seat pocket from the seat cushion in order to grip directly into the gap between the backrest and the seat cushion. However, there is the danger or dirtying the seat by the mounting plate of the robot. Even if this dirtying does not happen it means a further step of work to loosen the seat pocket and to put on again the seat pocket after mounting of the seats in the chassis. It is an disadvantage that the vehicle seat is not protected during robot mounting.
Vehicle seats have for 30 to 35 times contact with workers and other persons from the manufacture of the seat by the provider up to the delivery of the vehicle to the buyer, so that there is a reasonable danger of dirtying. To counteract this danger of dirtying the described seat covers made from plastic film are known, which often are put on the seat at the place of the seat manufacturer, at the latest at the place of the vehicle manufacturer. These seat covers are put on the seats, in particular the seat of the driver, and removed before delivery to the buyer. Such seat covers for new cars do not substantially differ from such seat covers which are used during repair or inspection. They may be made from comparatively thicker plastic film serving for the heavier use.
A seat cover of the type described above is known from DE 42 10 232 C2. The seat cover has a pocket on each of its end regions, whereby the seat pocket serves to receive a part of the seat cushion and the backrest pocket is adapted to receive a part of the backrest of the seat. The seat cover has a front layer, which is designed longer than the sum of the usable length of the backrest and the seat cushion. Due to this longer designed front layer it is possible to fold the front layer in this region generating a fixing fold and to clamp this fixing fold in the gap between backrest and seat cushion. The fixing fold is closed on both sides of the seat. The fixing fold serves mainly for fixing the seat cover in the region of the gap. The fold is clamped by the tension being present usually between backrest and seat cushion. This is advantageous because the part of the front layer protecting the backrest and the part of the front layer covering the seat cushion are held closer and tighter on the seat. There is the further advantage that the danger of displacement of the seat cover is substantially reduced, in particular in the region of the gap, so that there are practically no surfaces of the seat which are not protected. A vehicle seat protected by a seat cover of the described type may be used for robot mounting also using a mounting plate, but without penetrating the front layer. The fixing fold is pressed into the gap between backrest and seat cushion already at the place of the manufacturer of the seat. By doing this the seat cover is fixed additionally on the vehicle seat. The putting in of the mounting plate of the robot at the assembly line gives no variation of the position of the seat cover with respect to the vehicle seat.
A further seat cover is known from DE-B 16 30 878. During its manufacture a tubular film of plastic is cut lengthwise. The thus appearing both edges are displaced from each other and laid down in flat condition on the other material of the tubular film. By doing this a flat double-layered film is formed. The plastic film is folded in the region of both free edges left and right of the direction of production. The folded regions forming a rear layer will be connected with the front layer by transverse welded seams, i.e. weldings running across the direction of production. Thus two pockets are formed which normally differ in depth, the one being adapted to receive the backrest and the other being adapted to receive and surround the seat cushion of the vehicle seat. It is the side of the tubular film or the seat cover respectively which is called the front layer because it is the layer positioned in front when the seat cover is put on the vehicle seat and thus protecting the seating of the seat cushion and the front surface of the backrest. The other layer of the seat cover is called the rear layer because it is the layer which in mounted position protects the rearwardly and downwardly directed parts of the vehicle seat. Such known seat covers surround the vehicle seat more or less loosely. Due to this there is the danger of displacement of the seat cover during use. In the region between the seat cushion and the backrest unprotected surfaces appear being more or less large with the danger of dirtying during use. The seat pocket protects parts of the seat cushion and the backrest pocket protects parts of the backrest. But there remain parts of the surfaces of the seat unprotected. This is especially the case with surfaces in the downwardly directed part of the seat cushion, with surfaces in the link region of the seat, and with surfaces in the lower region of the downwardly directed part of the back of the backrest. These surfaces can be dirtied during use which is clearly to be seen and especially disadvantageous with seats made from light coloured leather.